23 ml drawing ink for technical pens, single bottle. Compatible with Isograph and other needle-type drawing pens. Available in black, blue, red, green, and white. Key benefits Reliable refills for technical drawing pens: formulated to feed consistently for precise line work and to reduce interruptions during drafting and illustration. Clear color options for organization and detail: choose from black, blue, red, green, or white to suit drawing, marking, or color-coding needs. Compact, single-bottle supply: 23 ml volume fits easily in a studio kit or toolbox and provides multiple refills for regular use. What this ink does for you Keeps technical pens ready for fine, controlled work without frequent clogging or uneven flow. Helps maintain consistent line quality across drawings and diagrams by matching the needs of needle-point pens. Adds flexible color choices to support layering, annotations, and visual separation in technical and creative projects. Key attributes Function: refill ink for technical and needle-type drawing pens. Compatibility: compatible with Isograph drawing pens and similar technical pen models. Size: 23 ml bottle, single piece. Colors: black, blue, red, green, white. Performance: formulated for consistent feed and precise line reproduction when used with technical pens. Use scenarios Architectural drafting: refill technical pens to produce crisp plan lines and annotations in monochrome or color-coded layers. Engineering and technical diagrams: maintain even ink flow for detailed schematics, dimension lines, and notes that require accuracy. Illustration and graphic work: support fine-line illustrations, overlays, and colored details where controlled pen performance is essential. Packaging and handling note Supplied as one 23 ml bottle in the selected color. Store upright and keep cap closed when not in use to preserve ink condition. This ink is intended for use with technical drawing pens and for applications that demand precise, reliable line work and color options.